Regulus uREG, Руководство пользователя

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uREG User Manual
74
13. MEASUREMENTS
The
u REG
unit has been designed for two purposes: the primary aim to provide protective
functions and, additionally, to take electrical measurements during operation of a substation
bay.
Provision of both objectives requires regular basic measurements of bay electrical
parameters. The
u REG
unit measures 12 essential analogue value, the base for provision of
protective criteria. Depending on hardware configurations, these measurement can be as
follows:

three phase currents: IL1, IL2, IL3 (from module CT-0 );

three line-to-line voltages: UL12, UL23, UL31 (from module VT-0 );

two currents: zero sequence I0 and Ig (from module VT-0 );

zero sequence voltage U0 (from module VT-0 );

three voltages at inputs AUXI0, AUXI1, AUXI2 (from module VT-0 )
or

three phase currents: IL1, IL2, IL3 (from module CT-0 and VT-3 );

three line-to-line voltages in section 1: UL12, UL23, UL31 (from module VT-2 and VT-3 );

three line-to-line voltages in section 2: UL12, UL23, UL31 (from module VT-2 and VT-3 );

zero sequence voltage U0 in section 1 (from module VT-2 );

zero sequence voltage U0 in section 2 (from module VT-2 );

zero sequence current I0 (from module VT-2 );
The listed values constitute a set of measures source-related values. All source-related
values are routed to the device via input circuits, whose essential elements include current and
voltage instrument transformers, which provide necessary galvanic separation between input
terminals and internal circuits. Also, they perform preliminary adaptation of the signal to
features and ranges of measuring circuits inside the bay controller. Measurements of source-
related values are given as digital samples. In the computer of the mainboard (
MB ), which is
directly interfaced with the measurement path, samples of currents and voltages undergo
initial scaling and digital processing.
The
u REG
device uses true RMS of currents and voltages as the information about the
source value. To the highest extent possible, the RMS value represent power and energy
features of the function under co-presence of fundamental frequency harmonics. The synthesis
of the RMS value in
u REG
involves 50 Hz frequency harmonics, up to 13th harmonic (inclusive).
Based on the source values, derivative values are computed. These derivative values
entirely correspond to operational measurements in the bay. They include estimated
instantaneous three-phase active and reactive power values, moving average power values at
15-minute time slots and instantaneous tangent of the phase angle. Additionally, computation
procedures include cumulated bidirectional active and reactive energy values in time zones,
estimated loss energy in the line in time zones, peak power values in moving 15-minute time
slots in time zones, cumulated bidirectional total active and reactive energy values, and average
tangents of phase angles for the direction of energy outflow.
All measured source values and computed derivative values are converted to the SI units. If
requested by the operator, the values can be shown on the LCD screen of the unit, and if
requested by the supervisory computer, transmitted via communication interfaces as messages
of computer protocols. Both direction of result presentation are independent of each other.